Coherent Spin Manipulation and ESR on Superfluid Helium Nanodroplets
Coherent Spin Manipulation and ESR on Superfluid Helium Nanodroplets
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DOI：
10.1103/physrevlett.103.035302
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发表时间：
2009-07-17
影响因子：
8.6
通讯作者：
Ernst, Wolfgang E.
中科院分区：
文献类型：
--
作者：
Koch, Markus;Auboeck, Gerald;Ernst, Wolfgang E.
超流氦纳米液滴提供了一种多功能的基底来冷却原子和分子，并组装弱结合的复合物。由于缺乏自旋弛豫机制，He纳米液滴是分离开壳原子和创建自旋极化系统的理想选择。在这里，我们展示了通过磁偶极子跃迁的共振激发对这样一个系统的第一个相干操纵。对近50个拉比振荡的观测表明，种群迁移具有最小的减相。这也是ESR光谱首次应用于掺杂He纳米液滴。这种独特的环境导致了极其尖锐的线条和超精细分辨的光谱：这里给出的单个K-39和Rb-85掺杂原子的光谱表明费米接触相互作用的增加，我们可以将其作为液滴尺寸的函数来跟踪，反映了由于周围He引起的价电子波函数的畸变。
Superfluid helium nanodroplets provide a versatile substrate to cool atoms and molecules, and to assemble weakly bound complexes. Absence of spin-relaxation mechanisms makes He nanodroplets ideal to isolate open-shell atoms and create a spin-polarized system. Here, we show the first coherent manipulation of such a system by resonant excitation of a magnetic-dipole transition. Observation of approximate to 50 Rabi oscillations demonstrates coherent population transfer with minimal dephasing. Ours is also the first application of ESR spectroscopy to doped He nanodroplets. This unique environment results in extremely sharp lines and hyperfine-resolved spectra: those of single K-39 and Rb-85 dopant atoms presented here denote an increase of the Fermi contact interaction, which we can follow as a function of droplet size, reflecting the distortion of the valence-electron wave function due to the surrounding He.